Historically too, physical capabilities and social circumstances may have tended to have female killers use methods such as poisons etc rather than more blatant physical attacks etc. Medical forensic technology was also less advanced, and food safety less rigorous.

If a bunch of people died of a "bad batch" of food or a lover fell down the stairs, drowned etc after too much drink, what would the chances of an in depth-investigation in comparison to say somebody found beaten, strangled, or stabbed?

It's easy to not find something that you're not looking for, and easy to not be looking for it if you start with a biased assumption.

That said, this is a rather dark turn from the more wholesome content of the original post. I very much enjoyed the story as an example of checking one's bias and not assuming the worst of people. One should be careful, but being too much so means missed opportunities for what may end up becoming a beautiful friendship like we've seen here. Both individuals sound like the types of friends I wish I'd had when younger, and the types of adults I'd love to sit and enjoy a meal with.